1. Field of the Invention
The present Invention relates to a rectifier used in a vehicular alternating current (AC) generator (i.e., alternator) mounted in vehicles such as automobiles and tracks, and in particular, to the rectifier provided with cooling fins (or radiating fins).
2. Description of the Related Art
In general, most vehicles are provided with an alternating current generator, i.e., alternator. The known vehicular AC generator employs one high-side (i.e., positive-side) cooling fin and one low-side (i.e., negative-side) cooling fin and these fins are arranged so as to be overlapped in the direction along the rotary shaft of the generator, as disclosed by Japanese Patent Nos. 3820712 and 3374776.
However, in the above conventional cooling-fin structure provided with the one high-side cooling fin and the one low-side cooling fin, it is difficult to enlarge their heat dissipation areas. Thus the dissipation areas cannot be made larger, thereby being difficult to improve the cooling performance of the whole rectifier.
In addition, an electric potential is generated between the cooling fins. When conductive materials such as saline solution is packed between the cooling fins, there is a possibility of causing an electric short-circuit due to the mutually opposite polarities, which may result in stopping the generation. Hence, to avoid such problems, it is necessary to secure a predetermined-length gap between the mutually-polarity cooling fins. This encounters a limitation in shortening the axial size, thereby being difficult in producing a compact rectifier.
In contrast, when it is desired to give the same dissipation area to the respective high-side and low-side cooling fins, the cooling fin located at a downstream position in the cooling air flow hardly receives the cooling air, thus being deteriorated in its cooling performance.